Neil O'Brien has underestimated the sophistication of the Labour leader's approach.

The longer Tories keep underestimating Ed Miliband, the better for Labour. So I feel slightly disloyal in pointing out where and why Neil O’Brien got it wrong in his essay in this week's New Statesman.

First, Ed didn’t go from "joke" to 45% in the polls by chance. For two years, he has kept setting the political agenda. Time and again, commentators and politicians who didn’t take him seriously missed the importance of what he was saying and its resonance outside Westminster.

His phrase "squeezed middle" was met with derision. A year later it was the Oxford English Dictionary's "word of the year". Ed’s "producers vs predators" conference speech was taken as a sure sign he hadn’t got what it takes to be a "proper" political leader. Three months later, everyone was fighting to own responsible capitalism. And, now, as another banking scandal rages, it turns out that Labour has the best framework to understand what is going on. He pitched "responsibility at the top and the bottom" against the exclusively anti -poor rhetoric of the government’s welfare reforms and forced a debate about top pay.

Miliband’s judgement on these issues reflects a profound belief that Britain can be more different than most people in politics dare imagine. I don't think for one moment that David Cameron thought hacking Milly Dowler’s phone was a good idea, but he couldn’t imagine a politics without Rupert Murdoch’s influence. Ed could, which is why he made the right calls on BSkyB and Leveson. This week, George Osborne’s inability to see the banking crisis as anything but a chance to score political points has, once again, put the Tories on the wrong side of a strategic argument. Sorting out the City today is more important than who might have done what ten years ago.

None of us in Westminster have yet broken free of the public cynicism about all politicians. But, maybe, just maybe, people are beginning to understand that Ed Miliband does things differently. Maybe it’s not such a surprise that Labour has recovered rather faster than most of us thought possible.

Of course, the Tories certainly haven’t helped themselves. The NHS bill did not have to become a golden opportunity for Ed to hone his PMQs skills. The Budget did not have to be so incompetent. Labour's attack was only possible, though, because Miliband and Ed Balls had already defined fairness and growth as the two crucial budget tests.

But O’Brien’s biggest misjudgement is the belief that Miliband’s Labour is torn between radicalism and pragmatism, and that this choice has to be resolved one way or another. Ed Miliband is coming from a different place altogether. As a new Fabian book, The Shape of Things To Come, shows, his genuine radicalism stems from a deep belief that it is only through far-reaching changes in the economy, society and politics of Britain that we can deliver for those who want practical answers to practical problems

He's confident that the economy can be reshaped by an active state enabling successful private business; an ambition that goes beyond the odd token grant and investment that passes for Osborne's "industrial strategy". The rules of the game can be set to favour long-term investment, innovation, competition and better jobs. If we don’t, we won’t be able to pay our way in the world. But as importantly, too much of Labour’s public spending was driven by problems of failing markets. The cost of tax credits rose in an economy producing too many poorly-paid jobs. Housing benefit paid the cost of a private sector of limited supply, poor quality and high rent.

There are some in Labour who assume that progressive change is measured by the level of public spending. But the emerging consensus among those Ed has promoted is that there is no foreseeable point where the public spending taps are turned back on. The cost of an ageing population, the need to invest, and the impossibility of increasing taxes for the squeezed middle will see to that. So it is the construction of a different economy, one that offers through work what past governments delivered through redistribution, that will let Labour deliver its aims even in lean times. O'Brien's belief that Labour's spending instincts are bound to spill out misreads the way Labour's debate is going.

This is a radical change, although some elements of an active industrial policy were pioneered by Peter Mandelson at the business department before the 2010 election. But it also has the best chance of delivering what Britain’s worried, vulnerable and socially conservative voters want to see; the ones who increasingly thought Labour doesn’t stand for them any more; the ones who didn’t think the economy worked for them.

O’Brien is right to say there are many issues that remainchallenging for Labour, not least welfare. But it’s telling that he sees this as a tactical issue for the Tories. Adopt an unpleasant policy that will really hurt some people and challenge Labour to vote against it. The truth is that time is running out for that sort of politics. The public know what politicians are up to. They don’t like it.

While few people will vote for a party that is seen as soft on fiddling or downright idleness, maybe there’s a bigger prize in offering a welfare system that actually works better. Shifting investment from tax credits to affordable child care, or landlords' rents to bricks and mortar. Rewarding those who work and contribute over those who didn’t.

So Miliband might respond to O'Brien's false choice by saying that in these times, radicalism is the pragmatic option. But as one of the authors of The Shape of Things To Come says, "Ed's self confidence in speaking about morality and culture sets him apart from the 'left liberal' social democrat norm of the past 50 years". This is not radicalism unrestrained by the views of real voters. The tough issues like migration and welfare will be tackled but not, I suspect, by the occasional lurch to the right, but by building a vision of Britain's future that connects Miliband's radical instincts to the instinctive fairness of the British people.

In a few weeks' time, kids across the country will ask, "are we nearly there yet?" In truth, not yet. But there is a radicalism, coherence and optimism to Ed Miliband's politics. I hope Neil O'Brien continues to underestimate it.

The Shape of Things To Come: Labour’s New Thinking, edited by John Denham, is published by the Fabian Society and FEPS.